In terms of getting the dragon animation to appear you'll likely first have to copy all of the bam files (animations/images) that relate specifically to the monster animation in question. Monster animations generally have an M I think for a prefix (so MREMA1.bam for instance is one file for Remhoraz). Each one of these is going to correspond to either a different direction they are facing, a different approach they might be taking to attacking, or just general movement.

You've got the creature file already (but you may also need to give it a new name if its name lacks string references).

In the case of a monster you will also want to make sure that you've copied any relevant items they use (including their weapons). These might not be included (or may be named differently) between the two games.

You'll need to either copy the dialog and script files from BG2EE over to BGEE (by using a program like Near Infinity to extract them or by decompiling and recompiling them using WEIDU)

Finally, you'll need to modify a couple of different 2DA files and an IDS file (if you are just using this mod yourself you can make the changes within these files, otherwise you'll want to learn how to append files).

EXTANIM.2daEXTSPEED.2daANIMATE.IDS

What exactly you put in here will depend on what animation you are transfering over (so the values you see in other mods might not work for Dragons)